A U.S. Army gunner in the turret of an armoured vehicle scans the surrounding grounds during a mounted patrol in the village of Sanjeray in Kunar's Pech Rive Valley.

The United States would be in “very dire straits” and forced to redraw its national security strategy, if the Pentagon’s budget is cut by $500 billion over the next decade, according to Michele Flournoy, an Obama campaign adviser.

President Barack Obama in January released a revised national security strategy with a pivot to the Asia Pacific region while still countering the threat posed by al-Qaeda and projecting power in contested areas of the world.

Automatic cuts of $500 billion scheduled to take effect in January if Congress can not find a way around the so-called “fiscal cliff” looming, would “take away the resource space” on which the national security strategy is based, according to Flournoy, a former undersecretary of Defense for Policy who now serves on the Obama reelection campaign’s national security advisory committee.

The Pentagon would have to go back to the“drawing board” because it would have to give up “major pillars of American strategy,” Flournoy said at a Bloomberg Government lunch in Charlotte, North Carolina, where the Democratic National Convention opens today.

Automatic cuts of $1.2 trillion — half from defense, and half from other domestic discretionary spending – are required by a 2011 agreement to raise the U.S. debt limit. The reductions, slated to start in January 2013, were designed to push Congress to find other deficit-reduction proposals to replace these cuts. Senate and House lawmakers so far haven’t agreed on such a plan.